V(h). Chemical Safety - Acute Toxins

As defined by the Laboratory Standard, acute toxins are chemicals which may be fatal as a result of a single exposure or exposure of short duration. The OSHA Hazard Communication Standard, 29 CFR 1910.1200, defines a similar category, highly toxic chemicals, based on animal (rat) toxicity data using the following criteria:

However, a review of Material Safety Data Sheets reveals that these toxicity data are not available for many laboratory chemicals. As there is no definitive list of acute toxins, they will be defined here as a chemical which meets one or more of the following four criteria.

Animal toxicity data is available and meets the LD50 criteria listed above.

The container label or Material Safety Data Sheet identifies the substance as "acutely toxic", "highly toxic", "may be fatal if inhaled", "may be fatal if enters the bloodstream", or similar warning of acute toxicity.

It is on the list of examples in Appendix V(h)-B which was compiled from several sources as referenced, and includes: all DOT Poison A chemicals, and chemicals with a National Fire Protection Association "Health" rating of 4 for highly toxic chemicals.

The faculty member has knowledge that the chemical is an acute toxin.

B. Purchase Approval and Acute Toxin Protocols

There are two categories of chemical purchases that require approval prior to purchase: acute toxins as defined in Chapter V(h) and chemicals subject to Department of Homeland Security (DHS) reporting as 'chemicals of interest' that have thresholds at or below 15 pounds. Appendix V(a)-B is a compilation of the DHS list and the list of examples of Acute Toxins from Appendix V(h)-B. Please check all the criteria defining an Acute Toxin to determine if a chemical meets the criteria though it may not appear on the list of examples.

If approval to purchase the chemical is granted, an acute toxin protocol must be submitted.

A written protocol is required for any use of an acute toxin. The protocol must include the experiment procedure, necessary protective equipment, safety precautions, emergency procedures, user training and waste disposal. The protocol must be submitted to the Chemical Hygiene Officer and reviewed with other faculty, students and staff working in the lab. A protocol form is included in Appendix V(h)–A.

C. Personal Protective Equipment

Protective Clothing. Laboratory coats must be worn when handling greater than one liter of an acute toxin that is readily absorbed through the skin, as indicated by an "s" on the list. Laboratory coats used for this purpose must not be worn outside of the laboratory. Contaminated clothing must be removed immediately and disposed of or laundered separately from street clothes.

If hand contact is possible, gloves appropriate for the task and with resistance to the chemical involved must be worn. Disposable gloves must be discarded after every use and immediately after overt contact with an acute toxin. Non-disposable gloves must be designated for use only with acute toxins and must be decontaminated after every use.

Eye Protection. Appropriate eye protection must be worn as described in Chapter V(b).

D. Personal Hygiene

Hands must be washed with soap and water immediately after overt contact, at the completion of any procedure, and prior to leaving the laboratory. If eyes or other parts of the body are contaminated, they must be immediately washed or flushed as described in Chapter III.

E. Work Area Identification And Access

Each work area or laboratory where acute toxins are used on a regular basis must be labeled with a sign with the following or similar warning:

Caution -- Acute Toxin

When work areas have not been decontaminated or experiments involving acute toxins are left in progress, a “Do Not Enter” sign listing the name and phone number of the person to be contacted in case of emergency must be posted on the exterior door.

F. Handling And Storage Procedures

Work Surfaces. All work surfaces on which non-volatile acute toxins are used should be a smooth nonporous material or covered with stainless steel or plastic trays. The work surface or trays should always be decontaminated after the procedure is complete.

Containment Equipment. Procedures using volatile acute toxins and those involving solid or liquid acute toxins that may result in the generation of aerosols or airborne particles should be conducted in a fume hood, glove box or other containment device. Examples of aerosol generation procedures include: transfer operations, blending, open vessel centrifugation, and injection.

Vacuum Lines. Vacuum lines, other than water aspirators, should be protected (e.g., with an absorbent or liquid trap and a HEPA filter) to prevent entry of any acute toxin into the system.

Decontamination. Equipment and contaminated materials should be decontaminated using procedures that deactivate the acute toxin, if such procedures are available. If deactivation procedures are not available, the equipment should be rinsed with an appropriate solvent and the solvent collected as hazardous waste. Decontamination of the work area must be done whenever there has been overt contamination and at the end of each experiment. Ideally, the work area should be decontaminated daily. If a work area is not decontaminated prior to leaving for the day, a “Do Not Enter” sign must be posted, as described in Section F above.

Container Labeling. Containers in which acute toxins are stored must be labeled with, at a minimum, the chemical name and a warning indicating it is an acute toxin. In lieu of labeling individual containers, entire storage areas may be labeled.

G. Waste Disposal

Collection for Off-Site Disposal. All waste and contaminated materials must be collected for off-site incineration. The procedures outlined in Chapter XI for hazardous waste disposal should be followed.